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Gradually increasing durations of high temperature caused by climate change harm the health of individuals and then lead to death. This study aimed to investigate the relationship between durations of different daily mean air-temperature categories and mortality in China and forecast future mortality changes in China for 2020–2050 under Representative Concentration Pathways (RCP)4.5 and RCP8.5 scenarios. The daily mean air temperature was divided into 10 categories, and the days under each air-temperature category were counted during the period of 2000–2015. Then, the connection between the days of each of the 10 air-temperature categories and mortality was established using the semi parametric regression model. Results indicate that the days of the >32 °C category have the largest impact on mortality in China, with the death rate increasing by 23‰ for one additional day. Predictions reveal that mortality in China will increase 25.48% and 26.26% under the RCP4.5 and RCP8.5 scenarios, respectively. Moreover, the mortality of 86 regions in western China will increase 30.42%. Therefore, in the future, the increasing duration of days of high temperatures will raise the mortality rate in China and aggravate the mortality gap between developed and underdeveloped regions. [ABSTRACT FROM AUTHOR]

This paper examines the effects of extreme temperatures on mortality rates, using random year-to-year variation in temperature based on county-level panel data from China. The analysis finds a robust, U-shaped relationship between temperature and mortality rates, indicating that extremely cold or hot temperatures lead to excess deaths. The heat-related (cold-related) effect is 3.5 times (3.2 times) as large as previous findings that used U.S. data, and it is especially large for the elderly population, mainly due to excess deaths caused by cardiovascular diseases. Applying these results to climate change predictions from Hadley Centre Global Environmental Model shows that by 2061–2080 the annual mortality rate is likely to increase by 14.2% if global greenhouse gas emissions continue to rise throughout the 21st century, the estimated health cost of which is around 0.98 trillion Chinese Yuan per year. The paper also explores households' adaptation behaviors to extreme temperatures. It finds that although urban households adaptively increase energy consumption when they are exposed to cold temperatures and purchase more air conditioners on hot and cold days, rural households are unresponsive to temperature fluctuations. This finding implies that rural people may be more resource constrained and suffer more when extreme temperatures occur. [ABSTRACT FROM AUTHOR]

Climate change has resulted in an increase in drought severity in the species-rich tropical and subtropical forests of southern China. Exploring the spatiotemporal relationship between drought-tolerance trait and tree abundance provides a means to elucidate the impact of droughts on community assembly and dynamics. In this study, we measured the leaf turgor loss point (πtlp) for 399 tree species from three tropical forest plots and three subtropical forest plots. The plot area was 1 ha and tree abundance was calculated as total basal area per hectare according to the nearest community census data. The first aim of this study was to explore πtlp abundance relationships in the six plots across a range of precipitation seasonality. Additionally, three of the six plots (two tropical forests and one subtropical forest) had consecutive community censuses data (12–22 years) and the mortality ratios and abundance year slope of tree species were analyzed. The second aim was to examine whether πtlp is a predictor of tree mortality and abundance changes. Our results showed that tree species with lower (more negative) πtlp were more abundant in the tropical forests with relative high seasonality. However, πtlp was not related to tree abundance in the subtropical forests with low seasonality. Moreover, πtlp was not a good predictor of tree mortality and abundance changes in both humid and dry forests. This study reveals the restricted role of πtlp in predicting the response of forests to increasing droughts under climate change. [ABSTRACT FROM AUTHOR]

Using non-accidental mortality records from 195 sites and 11 model simulations from the Coupled Model Intercomparison Project phase 6, we assessed future avoidable heat-related deaths associated with emission mitigation after accounting for population changes in China. Without human-induced climate change in the 21st century, China's heat-related mortality would drop by 48–72% (95% confidence interval (CI): 40–76%), especially at high latitudes and altitudes (up to 80%). Nationally, 15,576–87,612 (95% CI: 6605–106,736) heat-related deaths per year would potentially be avoided by reducing emissions. For most of China, temperature changes dominate the variation in heat-related deaths, while in Central and South China, population changes will have a greater influence. These not only reinforce the necessity of mitigating emissions but also suggest that adjusting population structure and spatial distribution could be applied in some areas to minimize warming impacts on public health. Notably, given that abatement will hardly bring immediate success within the next twenty years, more healthcare infrastructures are urgently needed to manage potential growing heat risks. Particularly in Northwest and South China, where future heat-related deaths would still be 110–140% of current levels (1995–2014) even without anthropogenic warming. We also found that without historical human-induced emissions, China's low level of technology (medical and economic) might increase current heat-related mortality by 57%, even though warming could be mitigated. Consequently, we believe that mitigating climate change risks also requires consideration of the economic/medical losses from lowering emissions. [ABSTRACT FROM AUTHOR]

Recent studies have reported a variety of health consequences of climate change. However, the vulnerability of individuals and cities to climate change remains to be evaluated. We project the excess cause-, age-, region-, and education-specific mortality attributable to future high temperatures in 161 Chinese districts/counties using 28 global climate models (GCMs) under two representative concentration pathways (RCPs). To assess the influence of population ageing on the projection of future heat-related mortality, we further project the age-specific effect estimates under five shared socioeconomic pathways (SSPs). Heat-related excess mortality is projected to increase from 1.9% (95% eCI: 0.2–3.3%) in the 2010s to 2.4% (0.4–4.1%) in the 2030 s and 5.5% (0.5–9.9%) in the 2090 s under RCP8.5, with corresponding relative changes of 0.5% (0.0–1.2%) and 3.6% (−0.5–7.5%). The projected slopes are steeper in southern, eastern, central and northern China. People with cardiorespiratory diseases, females, the elderly and those with low educational attainment could be more affected. Population ageing amplifies future heat-related excess deaths 2.3- to 5.8-fold under different SSPs, particularly for the northeast region. Our findings can help guide public health responses to ameliorate the risk of climate change. Global warming is expected to increase mortality due to heat stress in many regions. Here, the authors asses how mortality due to high temperatures changes in China changes for different demographic groups and show that heat-related excess mortality is increasing under climate change, a process that is strongly amplified by population ageing. [ABSTRACT FROM AUTHOR]

This paper explores the historical relationship between weather fluctuations and mortality evolution in China. Using panel data on the annual provincial mortality rate and daily weather variables for the 1964–2008 period, we applied a dynamic model structure with sufficient controls to estimate the short-term effects of temperature shocks on China's mortality rate. Our main results show that an additional 1 °C rise in average temperature in a given year increases the annual mortality rate by an average of 3.2%. In addition, days with daily average temperatures exceeding 27 °C (30 °C) are associated with an increase in the annual mortality rate of nearly 0.1% (0.2%) or approximately 9,520 (19,040) additional deaths. In contrast, extremely cold days do not have these effects. By applying a hybrid model structure (the long difference approach) to examine the medium-term effects of temperature changes, we find that there is little evidence of overall adaptation to high temperatures when moving from the short term to the medium term. In addition, by introducing interactions between temperatures and potential modifiers such as access to doctors, hospital beds, air conditioning and refrigerators, we determined that only residential air conditioning played an important role in mitigating the temperature-mortality relationship. However, the penetration of air conditioning in China is still relatively low. These findings indicate that climate change could partially explain the historical phenomenon of China's rising mortality rate during the unprecedented economic boom experienced since the 1980s. • Increases in the number of extreme hot days increase annual mortality rate. • Little evidence of adaptation when moving from short run to medium run. • Residential air conditioning has played an important role in mitigating the temperature-mortality relationship. [ABSTRACT FROM AUTHOR]

The ability to survive annual temperature minima could be a key determinant of distribution limits for insects under global climate change. Recent studies have suggested that insect aquaporins are indispensable for cellular water management under conditions that lead to dehydration and cold stress. Aquaporins are integral membrane water channel proteins in the major intrinsic protein superfamily and promote selected solutes and the movement of water across biological membranes. We cloned and characterized nine full-length aquaporins from Dendroctonus armandi (DaAqps), the most destructive forest pest in the Qinling Mountains of Shaanxi Province, China. Eight of the DaAqps belong to three classical aquaporin grades, including the Drosophila integral protein, the Pyrocoelia rufa integral protein, the entomoglyceroporins and one that belongs to the unorthodox grade of aquaporin 12-like channels. The DaAqps were increasingly expressed during different developmental stages and in different larval tissues, and expression peaked in mid-winter. They were tested under cold conditions for different lengths of time, and the expression of almost all DaAqps was down regulated with decreasing temperatures and long-term exposure to cold conditions. However, when the lowest temperatures were reached, the levels were immediately upregulated. These genes indicate that cold tolerance can improve through mortality responses at low temperatures after RNA interference of DaAqps. In our study, we analyzed the molecular response, expression patterns, and RNA interference of DaAqps and clarified the crucial role of protective compounds (aquaporins) underlying D. armandi cold tolerance and provide a new pest control method. [ABSTRACT FROM AUTHOR]

The frequency, intensity, and duration of extreme temperature events are expected to rise in the future and increase the related health risks of human beings. Using a novel, nationwide dataset that links extreme temperature and mortality, we estimated the short-term and long-term effects of extreme temperature on mortality in China during 2002-2013. Both extreme hot and extreme cold had immediate and long-term effects on all-cause mortality. Annual deaths per 100,000 people due to extreme hot and cold in the long term were considerably larger compared to the short term. The change in cold spell duration indicator exhibited the greatest effects on annual deaths per 100,000 people among a set of extreme weather indicators. Furthermore, cities with low economic development levels were more vulnerable to extreme temperature, compared to cities with high economic development levels. Our results offer important policy implications for developing a regional-specific extreme weather plan to handle extreme temperature events in China. [ABSTRACT FROM AUTHOR]

We aim to explore the Minimum Mortality Temperature (MMT) of different cities and regions, and that provides evidence for developing reasonable heat wave definition in China. The death data of 31 Chinese provincial capital cities from seven geographical regions during 2008-2013 was included in this study. In the first stage, a DLNM (Distributed Lag Non-linear Model) was used to estimate the association between mean temperature and mortality in a single city, then we pooled them with a multivariate meta-analysis to estimate the region-specific effects. The range of MMT was from 17.4 °C (Shijiazhuang) to 28.4 °C (Haikou), and the regional MMT increased as the original latitude decreased. Different cities and regions have their own specialized MMT due to geography and demographic characteristics. These findings indicate that the government deserves to adjust measures to local conditions to develop public health policies. [ABSTRACT FROM AUTHOR]

Background: Global climate change is one of the most serious environmental issues faced by humanity, and the resultant change in frequency and intensity of heat waves and cold spells could increase mortality. The influence of temperature on human health could be immediate or delayed. Latitude, relative humidity, and air pollution may influence the temperature-mortality relationship. We studied the influence of temperature on mortality and its lag effect in four Chinese cities with a range of latitudes over 2008-2011, adjusting for relative humidity and air pollution.Methods: We recorded the city-specific distributions of temperature and mortality by month and adopted a Poisson regression model combined with a distributed lag nonlinear model to investigate the lag effect of temperature on mortality.Results: We found that the coldest months in the study area are December through March and the hottest months are June through September. The ratios of deaths during cold months to hot months were 1.43, 1.54, 1.37 and 1.12 for the cities of Wuhan, Changsha, Guilin and Haikou, respectively. The effects of extremely high temperatures generally persisted for 3 days, whereas the risk of extremely low temperatures could persist for 21 days. Compared with the optimum temperature of each city, at a lag of 21 days, the relative risks (95 % confidence interval) of extreme cold temperatures were 4.78 (3.63, 6.29), 2.38 (1.35, 4.19), 2.62 (1.15, 5.95) and 2.62 (1.44, 4.79) for Wuhan, Changsha, Guilin and Haikou, respectively. The respective risks were 1.35 (1.18, 1.55), 1.19 (0.96, 1.48), 1.22 (0.82, 1.82) and 2.47 (1.61, 3.78) for extreme hot temperatures, at a lag of 3 days.Conclusions: Temperature-mortality relationships vary among cities at different latitudes. Local governments should establish regional prevention and protection measures to more effectively confront and adapt to local climate change. The effects of hot temperatures predominantly occur over the short term, whereas those of cold temperatures can persist for an extended number of days. [ABSTRACT FROM AUTHOR]

Aim: There are uncertainties regarding the modification effects of season and temperature on the relationship between air pollution and mortality. This study aims to examine the effects of season and temperature on mortality associated with particulate matter less than 10 μm in diameter (PM) in Tianjin, China. Methods: Time-series analysis was used to explore the modification effects of season and temperature on the association between PM and cause-specific mortality in Tianjin between 2006 and 2009. The causes studied were overall non-accidental mortality and subcategories of cardiovascular, respiratory, cardiopulmonary, stroke, and ischemic heart diseases (IHD). Results: The association between PM and mortality showed a strong seasonal pattern and the effects of PM on cause-specific mortalities were strongest for high temperature days. Generally, the adverse effects were stronger in summer than for other seasons, except for respiratory mortality. In the summer period, a 10 μg/m increase in PM at 0-1 days was associated with an increase in mortality for non-accidental (0.95 %, 95 % confidence interval [CI]: 0.45, 1.45), cardiovascular (1.40 %, 95 %CI: 0.77, 2.03), cardiopulmonary (1.37 %, 95 %CI: 0.77, 1.98), IHD (1.55 %, 95 %CI: 0.73, 2.37), and stroke (1.27 %, 95 % CI: 0.37, 2.12) causes. The overall increase in mortality per 10 μg/m increase in PM was 0.42 % (95 %CI: 0.26, 0.58) for non-accidental, 0.41 % (95 %CI: 0.21, 0.62) for cardiovascular, 0.46 % (95 %CI: 0.26,0.65) for cardiopulmonary, 0.57 % (95 %CI: 0.30, 0.84) for IHD, and 0.32 % (95 %CI: 0.03,0.61) for stroke. At high temperatures (≥23.8 °C), a 10 μg/m increase in PMat 0-1 days was associated with an increase in mortality of 0.90 % (95 %CI: 0.61,1.19) for non-accidental, 1.01 % for cardiovascular, 1.40 % (95 %CI: 0.55, 2.27) for respiratory, 1.06 % (95 %CI: 0.71, 1.41) for cardiopulmonary, 1.47 % (95 %CI: 1.00, 1.94) for IHD, and 0.75 % (95 %CI: 0.24, 1.28) for stroke. In addition, the PM effects of high temperature days were stronger for those aged 65 years and over. Conclusion: Season and temperature could modify the adverse effects of PM. An increase in hot summer days caused by climate change may enhance the risks of air pollution on human health. More attention should be paid to older populations, especially in summer and days with high temperatures. [ABSTRACT FROM AUTHOR]